An online payment service which can be used to send money from one person to another via their website, buy theings from online stores, or transfer money via your cell phone. Paypal is owned by Ebay Inc.
An online escrow company that acts as a middleman to help process transactions between providers of services and their consumers.
I use Paypal for all my websites because of its reliability and ease of use, not to mention I earn over a million every few months using Paypal because customers trust it.